Turbulent smelting chamber with air supply collars



R. WIESER June 1', 1965 TURBULENT SMELTING CHAMBER WITH AIR SUPPLY COLLARS Filed Feb. 26. 1962 United States Patent 3,186,382 TURBULENT SMELTING CHAMBER WITH AIR SUPPLY COLLARS Rudolf Wieser, St. Andra im Lavantale, Carinthia, Austria, assignor to Firma Durrwerke'Aktiengesellschaft, Ratingen, Austria, a corporation ofAustria Filed Feb. 26, 1962, Ser. No. 175,581 7 Claims priority, application Austria, Mar. 21, 1961,

A 2,293/ 61 7 Claims. (Cl. 122-235) The present invention relates to a vertical turbulence I smelting chamber for high-pressure steam boilers and air heater boilers for gas turbines with air supply collars.

Previously, vertical turbulence smelting chambers were constructed with slag separator collars formed from water pipes. The first of these designs had a relatively short separator collar which did not project too deeply into the smelting chamber, in order not to break up the combustion chamber too much. It proved, however, that the very hot flame gases, which are subjected to a strong lift, flow round the short collar very quickly. The lower part of the smelting chamber was therefore only slightly affected by the flame gases and the combustion was carried away into the secondary chamber of the boiler. As a result, vertical turbulence smelting chambers were constructed with long slag separator collars. These ,pro-

ject very deeply into the smelting chamber, under the lower edge of the burners. As a result the heat-reducing surface of the smelting chamber was greatly increased and the ignition conditions were impaired by a reduction of the radiation of heat, from the flame already burning, on the injected fuel. Owing to the instability of the flame flow, the result was a unilateral flow through the smelting space, despite the longer separator collar. Furthermore, a vertical, turbulence smelting chamber has been disclosed in which a part of the combustion air a is injected as tertiary air through nozzles arranged in annular form in the top of the smelting chamber; by this means a separator collar is formed, during operation, from air jets.

In the case of large smelting chambers I I this type of design does create, however, the problem of sufiicient depth of penetration of the tertiary air currents into the smelting chamber.

It is, therefore, one object of the present invention to provide a vertical turbulence smelting-chamber for highpressure steam boilers and air heater boilers for gas turbines with air supply collars, which avoids the disadvantages of the known structures.

It is another object of the present invention to provide a vertical turbulence smelting chamber for high-pressure steam boilers and air heater boilers for gas turbines with air supply collars, which comprises a vertical turbulence smelting chamber fitted with a double-walled closely-set supply collar made of cooling pipes and extending vertically to about one-third of the height of the smelting chamber. Through this double-walled supply collar flows a part of the combustion air, to which a cooling gas can be admixed for the regulation of the temperature of the smelting chamber, to reduce the evaporation of the slag, to the outlet nozzles at the lower end of the collar. These nozzles form a ring of air and/.or gas outlet ports, through which the medium is injected obliquely to the axis of the smelting chamber in the direction of the flame eddy, or against it or directly downwards instead. In this way, during operation, the air supply collar, consisting of water pipes, is extended by a collar of air or gas streams in the shape of a hyperbola, a truncated cone or similar to a cylinder.

The heat-reducing effect of the short air supply collar is relatively small. The collar, however, substantially increases the depth of penetration of the tertiary air "ice streams. The kinetic energy of these streams acts against the lift of the flame gases and so leads to a good flow through the lower part of the smelting chamber and favorably affects the eddy-effect of the flame. The tertiary air currents also counteract the formation of a unilateral flow through the smelting space and increase the binding effect upon the slag. I

Furthermore, the partial load smelting limit is reduced by a better heating of the floor of thesmelting chamber and of the outlet hole of the slag. The tertiary air may amount to 20-25% of the total combustion air.

With these and other objects in view, which will become apparent in the following detailed-description, the present invention will be clearly understood in connection With the accompanying drawing, in which:

FIGURE 1 is an axial section of the turbulentsmelt supply collar.

Referring now to the drawing, at the smelting chamber 1 having a polygonal or circle-like cross-section, the walls of which are formed of cooling pipes 2, the burners 3 are arranged such that in a plan view their axes are tangential to a burner circle 4. Into the upper third of the smelting chamber 1 projects the supply collar 5, which is substantially in the form of a truncated cone and whose walls consist of cooling pipes 6. Instead of the horizontal coiling of the pipes 6, it is also possible to have a vertical coiling thereof (not shown). The cooling pipes 6 are welded together close to one another and are pegged on the outer surfaces. halves are designed as slag dropping edges 7. Between the latter are arranged the actual tertiary air nozzles 8.

FIG. 4 discloses one embodiment of a developed cylindrical section along the lines 4-4 of FIG. 3, showing how the division of the lower annular outlet cross-section of the supply collar 5 into individual nozzles 8 is effected by dividing plates 9. In this embodiment the nozzle axes are directed vertically downwards. The developed cylindrical section disclosed in FIG. 5 is a secondembodiment in which the axes of the tertiary air nozzles 8 are directed obliquely from the bottom edge of the supply collar 5.

The tertiary air nozzles 8 do not need to be arranged absolutely symmetrical with respect to rotation at the bottom end of the supply collar 5. It will be advantageous to have a closer arrangement of the nozzles immediately around the pulverized-coal burner 3 (not shown).

The air supply collar 5 is connected at its upper end to the tertiary air channel 5a through intermediate channels.

The feed pipeslt) to the cooling pipes 6 of the air supply collar 5 are taken through the bottom'of the smelting chamber 1; they are connected regularly at the bottom edge of the air supply collar 5 and serve as slag outflow pipes. j

A wing grid 11 of cooling pipes, substantially symmetrical with respect to rotation, FIG. 1 showing only an outline of one wing, may be provided inside the air supply collar 5, in order to break up the twist of the flame gases at the outlet of the smelting chamber 1 and, by removing the centrifugal force effect, to reduce the fouling of the transfer diffuser 12 to the secondary combustion chamber.

-It may be mentioned further that the proposed design would be well applicable to the combustion of material The lower edges of the two collar diflicult'to ignite or to burn 3 i r V (coke, refuse, etc.). Owing to its lining with tamped clay, the smelting chamber would act here as an ignition chamber. a I

To obtain faultless ignition and complete combustion of the coke, refuse, etc, respectively, an annular ignition flame operated with fuel oil or gas could be employed, burning downwards from the supply collar 5. The oil or gas'burners are to be arranged at the bottom end of the supply collar 5 so as tobe symmetrical with respect to rotation. The oil or gas piping supply would have to be eifected through the double-Walled air supply collars 5. The bottom of the chamber 1 would have to be made steeper, in order to allow the dry ash to slide down.

- The particularadvantage of the annular ignition flame is that its very hot flame gases do not impinge directly on the chamber lining, thus reducing fouling, and that the primary fuel injected through the burners 3 is compelled to flow through the film of the hot ignition flame, hence guaranteeing ignition and combustion.

While I have disclosed several embodiments of the present invention, itis to be understood that these embodirnents are given by exampleonly andnot in a limiting sense, the scope of the present invention being determined by the objects andthe claims.

I claim:

steam boilers and air heater boilers of gas turbines,

said chamber including Wall means forming a combustion chamber, I r

said combustion chamber having an opening "at its bottom and comprises a plurality of-cooling pipes disposed in a substantially circular arrangement and extending along said wall means substantially vertically mainly on the bottom of said combustion chamber around said opening,

said opening being adapted to discharge slag,

a supply collar projecting from the top of said cooling pipes of said combustion chamber into the latter to operate as a flame outlet, I

said supply collar being spaced from said wall means and constituting a means for the supply of air and gas into said combustion chamber,

said supply collar defining a throat at itslower end and being of double-walled construction, the latter including an outer collar wall and an inner collar wall, both said outer collar wall and said inner collar wall terminating atthe bottom of said throat,

said supply collar having further at its lower end an annular outlet aperture for air and gas, respectively,

both of said walls of said supply collar being formed of cooling pipes, V v

a ring of outlet nozzles disposed in said outlet aperture of said supply collar,

means for supplying a fuel and air mixture by means of burners, I

said burners being disposed tangentially to a combustion circle in'said chamber, and

said burners being disposed between said wall means and said collar.

2. The turbulence smelting chamber, as set forth in claim 1, wherein the axes of said outlet nozzles are directed obliquely to said combustion chamber axis in the direction of the flame eddy.

3. The turbulence smelting chamber, as setforth in claim 1, wherein the axesof said outlet nozzles are directed obliquelyto said combustion chamberaxis against the flame eddy.

4., The turbulence smelting chamber, asset forth in claim 1, wherein the axes of said outlet nozzles are direct obliquely to said combustion chamber-axis axially parallel downwards. i

5. The turbulence smelting chamber, as set forth in claim 1, wherein said outlet nozzlesare arranged more closely in the region of said burners. I

6; The turbulence smelting'chamber, as set forth in claim 1, which includes means for admixing cooling gas with combustion air flowing through said supply collar,

' to regulate the temperature of said combustion chamber.

- 7.'The turbulence smelting chamber, as set forth in claim 1, wherein said burners are arranged at the lower end of said supply collar;

References Cited by the Examiner V UNITED STATES PATENTS 3,025,844

4/61 Great Britain.

OTHER REFERENCES German printed application 1,096,532, Walther & Cie, printed Jan. 5,1961, Kl. 24, L 8.

' PERCY L. PATRICK, Primary Examiner.

FREDERICK L. MATTESON, 111., Examiner. 

1. A TURBULENCE SMELTING CHAMBER FOR HIGH-PRESSURE STEAM BOILERS AND AIR HEATER BOILERS OF GAS TURBINES, SAID CHAMBER INCLUDING WALL MEANS FORMING A COMBUSTION CHAMBER, SAID COMBUSTION CHAMBER HAVING AN OPENING AT ITS BOTTOM AND COMPRISES A PLURALITY OF COOLING PIPES DISPOSED IN A SUBSTANTIALLY CIRCULAR ARRANGEMENT AND EXTENDING ALONG SAID WALL MEANS SUBSTANTIALLY VERTICALLY MAINLY ON THE BOTTOM OF SAID COMBUSTION CHAMBER AROUND SAID OPENING, SAID OPENING BEING ADAPTED TO DISCHARGE SLAG, A SUPPLY COLLAR PROJECTING FROM THE TOP OF SAID COOLING PIPES OF SAID COMBUSTION CHAMBER INTO THE LATTER TO OPERATE AS A FLAME OUTLET, SAID SUPPLY COLLAR BEING SPACED FROM SAID WALL MEANS AND CONSTITUTING A MEANS FOR THE SUPPLY OF AIR AND GAS INTO SAID COMBUSTION CHAMBER, SAID SUPPLY COLLAR DEFINING A THROAT AT ITS LOWER END AND BEING OF DOUBLE-WALLED CONSTRUCTION, THE LATTER INCLUDING AN OUTER COLLAR WALL AND AN INNER COLLAR WALL, BOTH SAID OUTER COLLAR WALL AND SAID INNER COLLAR WALL TERMINATING AT THE BOTTOM OF SAID THROAT, 